Have You Tried

Lattice Multiplication!

Have you taught your students to multiply with lattice multiplication? If not, they're missing out on a visual approach that most students seem to get and enjoy! Here's a couple of examples to see how it works.

Let's Multiply 38 X 42 the Lattice Way

Draw a 2-row 2-column box grid as shown in picture below. grid

Write the first number across the top and the second number down the right side of the grid as shown.

Now draw diagonal lines on each of the small squares as seen in the picture below.

Now here comes the multiplication part.

Multiply the first digit of number across the top by the first digit of the number down the side of grid. So for our example, we multiply the 3 times 4 and get 12.

Place the result in the box as pictured.

Next multiply the second digit of the number across the top of the grid by the same first digit of the number on the right side of the grid.

Place the result in the boxes as shown.

Now multiply the first digit of number across the top by the Second digit of the number down the side of grid.

Place the results in the boxes as pictured below.

Now multiply the second digit of number across the top by the Second digit of the number down the side of grid.

And now write your result in the boxes. You can see our example below.

Now add diagonally along the yellow arrows.

To get the answer, read or write the numbers down the left side and then across the bottom.

How about that! Pretty Cool, huh! Why don't you give it a try and see how you like it. Now how about trying it out with your own set of two digit numbers.